Universal serial bus (usb) thermal imaging camera kit

ABSTRACT

A system kit and a method for creating a thermal imaging camera by connecting an infrared radiation capturing device to an external platform are provided herein. The kit may include a front end module which may include an image capturing device comprising a micro bolometer detector; and a universal serial bus (USB) interface connected to the image capturing device. The kit may further include a backend module, comprising data sets which are specific to said micro bolometer detector and computer readable code which is executable by a computer processor located at a physical location other than the front end module, wherein said front end module is configured to obtain raw data from the micro bolometer detector and deliver it over the USB interface to said backend module, wherein said backend module code turns the raw data into thermal imagery and temperature readings.

TECHNICAL FIELD

The present invention relates to the field of thermal imaging camerasusing microbolometer detectors, and more particularly, to a kit enablingusing same on an off the shelf platform.

BACKGROUND

Prior to setting forth a short discussion of the related art, it may behelpful to set forth definitions of certain terms that will be usedhereinafter.

The term “capturing device” as used herein, is defined as any hardwarecombination of optics and sensor that is configured to produceelectrical signals representative of a scene in a pixel array format.Specifically, a capturing device as discussed herein, does not includeany image processing capability implemented therein beyond convertingthe raw data a data format appropriate for conveying.

The term “microbolometer detector” as used herein, relates to a detectorwhich includes an array of pixels, sealed in a vacuum package.

Infrared radiation with wavelengths typically between 7.5-14 μm strikesthe detector material, heating it, and thus changing its electricalresistance. This resistance change is measured and processed intotemperatures which can be used to create an image. Unlike other types ofinfrared detecting equipment, microbolometers do not require cooling

Many thermal imaging cameras make use of microbolometer detectors.Microbolometer detectors suffer from inherent technological issues whichmake them difficult to work with. When trying to transform themicrobolometer readings into good image quality, the raw data capturedfrom the detector has to be corrected with corrections algorithms andcorrection data sets. Typical corrections are non-uniformity correction(NUC), bad pixel replacement (BPR) and the like. These corrections arespecific to each individual detector, and need to be prepared in aspecial calibration environment, as it requires special tooling andknowhow (Oven, Blackbody, software and the like). More often,corrections are required not only per specific detector, but may also beneeded for a specific combination of detector and lens.

Currently available thermal imaging cameras are comprised of a lens, adetector and electronics. The electronic circuitry which is required forcapturing and processing the raw IR data and turning it into a videosignal is often called IR Engine or IR core. IR engines include amicrobolometer detector which is mounted onto a PCB board integratedwith additional appropriate circuitry needed for operating, controlling,powering, and reading the detector. Since currently available detectorsprovide raw data using a parallel electrical interface, either digitalor analog the IR engine includes some computing platform, such as FPGA,ASIC, DSP, CPU, and some form of memory in order to be able to performthe above mentioned corrections, as well as other signal and imageprocessing tasks. The fast development of global consumer electronicsmarket brought the availability of strong processing power to the handsof millions of users. Such processors can well replace the processingfunctions of an IR Engine.

Another challenge for making thermal imaging available for consumers isthe power requirements of a microbolometer based thermal imaging device.Due to its way of operation typical IR engine consume 0.6 W or above.Today's consumer electronics are often powered by low power batteries,as for example mobile cellphones, smartphones, tablets, etc. Addingthermal imaging capabilities to a mobile device as an add-on istherefore a challenging task.

SUMMARY

Embodiments of the present invention address the challenge ofinterfacing a power hungry micro bolometer infrared capturing front-end(FE) device with an external platform by using the USB (and specificallyUSB On The Go) interface which provides a way to connect a thermalimaging device to a mobile device as long as the imaging device drawsless than 500 mW.

According to one aspect, a system for creating a thermal imaging cameraby connecting an infrared radiation capturing device to an externalplatform is provided herein. The system may include: a micro bolometerbased capturing front-end (FE) device; and a universal serial bus (USB)interface connected to the FE, wherein the USB interface is configuredto deliver both data from the FE and power to the FE, wherein thedelivered data is only processed outside the system on an externalplatform connected to the USB interface. The external platformtransforms the raw-data into thermal imaging video and images by usingspecialty algorithms and a unique correction data set which is specificto the individual microbolometer detector in use.

These, additional, and/or other aspects and/or advantages of the presentinvention are: set forth in the detailed description which follows;possibly inferable from the detailed description; and/or learnable bypractice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of embodiments of the invention and to showhow the same may be carried into effect, reference will now be made,purely by way of example, to the accompanying drawings in which likenumerals designate corresponding elements or sections throughout. In theaccompanying drawings:

FIG. 1 is a high level schematic block diagram of a system according tosome embodiments of the invention;

FIG. 2 is a high level schematic block diagram illustrating anotheraspect of the system according to some embodiments of the invention; and

FIG. 3 is a high level schematic block diagram illustrating yet anotheraspect of the system according to some embodiments of the invention.

DETAILED DESCRIPTION

With specific reference now to the drawings in detail, it is stressedthat the particulars shown are by way of example and for purposes ofillustrative discussion of the preferred embodiments of the presentinvention only, and are presented in the cause of providing what isbelieved to be the most useful and readily understood description of theprinciples and conceptual aspects of the invention. In this regard, noattempt is made to show structural details of the invention in moredetail than is necessary for a fundamental understanding of theinvention, the description taken with the drawings making apparent tothose skilled in the art how the several forms of the invention may beembodied in practice.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings. Theinvention is applicable to other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

FIG. 1 is a high level schematic block diagram of a system 100 accordingto some embodiments of the invention. System 100 may include a front endmodule 110 which includes an image capturing device 10 which includes amicro bolometer detector. Front end module 110 may further include (orassociated with) a universal serial bus (USB) interface 130 coupled toimage capturing device 10. System 100 may further include a backendmodule 120 which includes data sets 124 which are specific to the microbolometer detector and computer readable code such as processing module122 which is executable by a computer processor located at a physicallocation other than the front end module.

In operation, front end module 110 may be configured to obtain raw data12 from the micro bolometer detector and deliver it as USB serializeddata 112 over USB interface 130 to backend module 120.

According to some embodiments of the present invention, backend module120 is configured to process the raw data 12 from the micro bolometerdetector delivered in USB serialized format 112 using the data sets 124and the computer readable code 122, to yield processed data 126.According to some embodiments of the present invention, the processeddata 126 comprise thermal imagery data. Processed data 126 may be in theform of still or video imagery but can also relate to any parametersextracted from the raw data without generating first video or stillimages.

According to some embodiments, computer readable code 122 may include anAPI (Application Programming Interface) that will enable softwaredevelopers to develop code for the external platform 20 that willutilize processed data 126.

According to some embodiments of the present invention, data sets 124may include correction datasets, usable for correcting the raw dataobtained from the microbolometer detector, wherein the correctiondatasets is based on a production profile of said microbolometerdetector. More specifically, the production profile comprises datarelating to at least one of: bad pixels, production deformations, andpixel level variations of said microbolometer detector.

FIG. 2 is a high level schematic block diagram illustrating anotheraspect of front end module 110 according to some embodiments of theinvention. Front end module 110 may include microbolometer detector 220which is implemented in a form of a photo-sensitive pixel array which isoptically coupled to optics 210 and electrically coupled to anElectronic interface 230 (e.g card) which is in communication with USBinterface 130.

FIG. 3 is a high level schematic block diagram illustrating yet anotheraspect of the system according to some embodiments of the invention. Anexternal platform 20 (being external in the sense that it is external tothe microbolometer detector and is located in a different physicallocation) may include a processor 380 and memory 330 onto which back endmodule 120 may be loaded. USB port 310 connected to processor 370 maycommunicate with USB interface 130.

Processor 380 may be further connected to transmitter 360, receiver 370,storage 350, power supply 320, and display 340. In operation, backendmodule may utilize any of the aforementioned components as resources forprocessing the raw data obtained from the microbolometer detector. Bydoing so, a user may enjoy the functionalities and computing power ofthe external platform with a very lean architecture of theaforementioned front end module 110 and back end module 120.

According to some embodiments of the present invention, front end module110 is further configured to receive a power supply from a power source320 via said USB interface 130.

According to some embodiments of the present invention, the power source320 is located within a platform 20 to which the processor 380 iscoupled. Alternatively, the power source is located outside a platformto which the processor is coupled.

According to some embodiments of the present invention, the backendmodule 120 may further include a (standard development kit) SDK softwaremodule configured to enable adding processing and control operationsapplicable to the microbolometer detector. The invention embodied in thekit formation may be sold as “USB thermal imaging KIT”. Advantageously,the USB micro bolometer thermal imaging kit will overcome the currentdifficulty of using thermal imaging by non-technicalusers/consumers/software developers. The Kit will enable users ofeveryday consumer electronics to easily “plug and play” a thermal camerato their existing computing devices. It will also allow softwareapplication developers to easily develop advanced thermal imagingapplications without the need to understand the complexities of anInfrared detector.

The kit will take advantage of the existing USB (Universal Serial Bus)standards, and in particular the ability for two electrical devices(e.g. a “host” computer and a camera) to be connected, thus enablingpower feed and communication exchange between “host” and camera. Thethermal kit Front End device consume very low power, and is the onlyavailable IR that will require no external power feed other than theones provided by the consumer device thru the standard USB connector(USB standard calls for <0.5 Watt).

Unlike most currently available thermal cameras, the front end will haveno shutter mechanism (Shutter is frequently used to allow periodic nonuniformity correction (NUC) operations in the field). In order tosimplify front end module 110, thus reducing its power consumption,almost all computational tasks may be carried out at the back end or bythe external platform. The kit will eliminate the need for complicatedpreparations and correction as it include the required magnetic data,software code, documentation and software tools that will allow the userto easily install and operate the USB thermal imager.

Additional thermal Imaging Applications (Apps) and development tools(SDK) will also be available for sell.

Advantageously, front end module is a very low power device whichincludes a micro bolometer thermal imaging detector. Front end module110 is a standalone USB device, it is powered by a USB power feed, andis providing raw video data via a standard USB serial interface. Thefront end will include the following functionality: Since power issupplied by the BE thru the USB connection, the front end will regulate,prepare and feed the micro bolometer detector (power supply needs to bevery well regulated and clean of interferences in order to get goodimage quality).

The front end will provide clock and synchronization signals to thedetector. Front end module 110 will control the detector 220 operation.Front end module 110 will read temperature measurements and otherparameters that are needed for optimal calculation by the BE. Front endwill read the data from the detector. The data could be either digitalor analog. In case the detector output is analog, the front end willsample and convert the data to digital. Front end will packetize andserialize the data from the detector and any other information needed,and will prepare the data into a format that is supported by the USBstandard.

It is important to note that front end could be materialized either bymounting a standalone microbolometer on a PCB with some additionalrelevant circuitry, or it could also be materialized by incorporatingall the required functionality on a single Chip or single Package(SoC—System on Chip, or SIP—system in Package). It is possible tointegrate USB serialization, A2D conversion, etc. inside the ROIC (Readout Integrated Circuit) of the detector, thus achieving a one chip frontend.

The external platform is an electrical device which has a computationalcapability, and which has an operating environment that supports USBconnectivity (For example: PC, Tablet, Laptop, and SmartPhone,). Thedevice will provide power and will communicate with the front end thru astandard USB interface (such as USB 2.0 and USB on the go “OTG”).

The device OS (operating system) will have the drivers andinfrastructure to easily identify the front end when connected in a“Plug and Play” mode. The BE will have development environment that willenable software developers to develop imaging application that utilizethe DSD data and the SDK (which includes software Library elements).

In accordance with some embodiments, USB interface 130 may be of variousforms (e.g. a “pig tail” with a connector, or a direct connector“dongle”), it needs to comply with a “Plug and Play USB” standard (miniUSB, Micro USB and the like.)

According to some embodiments a Dataset 124 may be implemented bysoftware executed on the processor of the external platform 20. A datapackage that include data which is specific to the particular front enddevice, which includes information such as NUC (Non UniformityCorrection data, and BPR (Bad Pixel Replacement) data. Dataset 124 maybe generated during the manufacturing process of the front end device,and is arranged as a data package so it could be read by the BE.

According to some embodiments, a Software Kit may further be distributedwith external platform: a kit which includes appropriate softwareelements. The code of the Kit is to be used on the BE platform. It willhandle the raw data acquisition from the USB IR detector and will applythe corrections using the Dataset 124. Specifically, The Software kitmay be configured to detect a one to one relationship between theDataset 124 and front end module 120. The detection may be achieved viaa device specific ID (e.g. Serial Number) that is stored on anon-volatile memory inside front end module 120, and referenced by datasets 124.

In the above description, an embodiment is an example or implementationof the invention. The various appearances of “one embodiment”, “anembodiment” or “some embodiments” do not necessarily all refer to thesame embodiments.

Although various features of the invention may be described in thecontext of a single embodiment, the features may also be providedseparately or in any suitable combination. Conversely, although theinvention may be described herein in the context of separate embodimentsfor clarity, the invention may also be implemented in a singleembodiment.

Embodiments of the invention may include features from differentembodiments disclosed above, and embodiments may incorporate elementsfrom other embodiments disclosed above. The disclosure of elements ofthe invention in the context of a specific embodiment is not to be takenas limiting their used in the specific embodiment alone.

Furthermore, it is to be understood that the invention can be carriedout or practiced in various ways and that the invention can beimplemented in embodiments other than the ones outlined in thedescription above.

The invention is not limited to those diagrams or to the correspondingdescriptions. For example, flow need not move through each illustratedbox or state, or in exactly the same order as illustrated and described.

Meanings of technical and scientific terms used herein are to becommonly understood as by one of ordinary skill in the art to which theinvention belongs, unless otherwise defined.

While the invention has been described with respect to a limited numberof embodiments, these should not be construed as limitations on thescope of the invention, but rather as exemplifications of some of thepreferred embodiments. Other possible variations, modifications, andapplications are also within the scope of the invention.

1. A system comprising: a front end module comprising: an imagecapturing device comprising a micro bolometer detector; and a universalserial bus (USB) interface connected to said image capturing device; anda backend module, comprising data sets which are specific to said microbolometer detector and computer readable code which is executable by acomputer processor located at a physical location other than the frontend module, wherein said front end module is configured to obtain rawdata from the micro bolometer detector and deliver it over said USBinterface to said backend module.
 2. The system according to claim 1,wherein the backend module is configured to process the raw data fromthe micro bolometer detector using the data sets and the computerreadable code, to yield processed data.
 3. The system according to claim1, wherein the processed data comprise thermal imagery data.
 4. Thesystem according to claim 1, wherein said front end module is furtherconfigured to receive a power supply from a power source via said USBinterface.
 5. The system according to claim 4, wherein the power sourceis located within a platform to which the processor is coupled.
 6. Thesystem according to claim 4, wherein the power source is located outsidea platform to which the processor is coupled.
 7. The system according toclaim 1, wherein the data sets comprise correction dataset, usable forcorrecting the raw data obtained from the microbolometer detector,wherein the corrections dataset is based on a special calibrationprocedure used during the manufacturing of said frontend module.
 8. Thesystem according to claim 7, wherein the correction dataset comprisesdata relating to at least one of: bad pixels, Non UniformityCorrections, Gain and Offset of said microbolometer detector reading. 9.The system according to claim 2, wherein the backend module furthercomprises a (Software development kit) SDK software module configured toenable adding processing and control operations applicable to themicrobolometer detector.
 10. A method comprising: providing a front endmodule comprising: an image capturing device comprising a microbolometer detector; and a universal serial bus (USB) interface connectedto said image capturing device; loading a backend module, comprisingdata sets which are specific to said micro bolometer detector andcomputer readable code onto a computer processor located at a physicallocation other than the front end module; and obtaining raw data fromthe micro bolometer detector and delivering it over said USB interfaceto said backend module.
 11. The method according to claim 10, furthercomprising processing the raw data from the micro bolometer detector atthe backend module, using the data sets and the computer readable code,to yield processed data.
 12. The method according to claim 11, whereinthe processed data comprise thermal imagery data.
 13. The methodaccording to claim 10, further comprising providing power supply to thefront end module from a power source via said USB interface.
 14. Themethod according to claim 13, wherein the power source is located withina platform to which the processor is coupled.
 15. The method accordingto claim 13, wherein the power source is located outside a platform towhich the processor is coupled.
 16. The method according to claim 10,wherein the data sets comprise calibration data, usable for calibratingthe raw data obtained from the microbolometer detector, wherein thecalibration data is based on a production profile of said microbolometerdetector.
 17. The method according to claim 16, wherein the productionprofile comprises data relating to at least one of: bad pixels,production deformations, and alignment of said microbolometer detector.18. The method according to claim 10, wherein the backend module furthercomprises a (standard development kit) SDK software module configured toenable adding processing and control operations applicable to themicrobolometer detector.